Mean Current Vector Based Online Real-Time Fault Diagnosis for Voltage Source Inverter fed Induction Motor Drives

This paper develops an real-time inverter fault diagnosis method for induction motor drives based on the subtractive clustering analysis of the stator current vector and a quick mean current vector calculation method. A subtractive clustering algorithm for analyzing the mean current vectors under both normal and faulty inverter condition is conducted off-line to verify the effectiveness of the mean current vectors for the inverter fault diagnosis. The amplitude and angle of the different mean current vector cluster are used to determine the fault modes. Furthermore, a single-data-shifting method is introduced to build up an array for the mean current vector calculation in the on-line fault diagnosis process. The simulation results verify that, based on the proposed method, the inverter faults can be detected within 1/4 period of fundamental frequency or even shorter time in both speed opened-loop and closed-loop induction motor drive system.